Lubricant



Patented Jan. 2,1945

UNITED STATE s PATEN OFFICE LUBBICAN T I Rush F. McCleary and Joseph E. Fields, Beacon, N. Y., assignors to The Texas Company, New York, N. Y., a corporation of Delaware No Drawing.

4 20 Claims.

This invention relates to a new and improved I lubricating composition and particularly to a hydrocarbon lubricating oil containing a new com-,

bination of additive ingredients.

The recent developments in the field of internal combustion engines designed for extremely high power outputs for extended periods of time have created such severe and exacting operating conditions as to necessitate an improvement in the refined hydrocarbon lubricating oils used in the lubricating systems thereof; The high engine speeds and high load characteristics of these en'- gines together with the use of new bearing alloys, such as cadmium-silver, copper-lead and silvercoated bearings, have caused a rapid deterioration ofthe'lubricating oils in service which results in a a build-up of carbonaceous deposits on the pistons and cylinders, wearing'and scratching of the pistons, cylinders, rings and liners, plugging of the oil rings, and corrosive attack on the bearing metals. The deterioration of the lubricating oil is manifested in the performance of the engine by ring-sticking, piston seizure, loss ofccmp'res-f sion, bearing failure, and in general by a loss of emciency and a greatly decreased running time,

It has been proposed to eliminate one or more of these 'undeslrable characteristics of the lubri- Application August 28, 1942, Serial No. 456,560

' 'bustion engine. It has been found that this combination of additive ingredients imparts combined extreme pressure properties, oiliness properties, dispersing properties, detergency, oxidation stamay and bearing protection to'the compounded oil.

The oil-miscible metal salts of a carbocyclic alkylol ether which constitute one of the compoeating oil by the incorporation of various chemical compounds possessing certain improving prop? erties. These compounds have been classified ac-' cording .to the properties imparted to the'oil as, for example, oiliness agents, V. I. improvers, film strength agents, anti-wear agents, dispersing agents, detergents, oxidation inhibitors, corrosion inhibitors, etc, Although these addition agents improve the lubricating oil in accordance-with their particular function when incorpor ted individually, no prediction can be made 2s to the degree of improvement, if any, when inoorpo-.-'

ratedin combination.

The present invention is based upon the dis-'- covery of a new combination of additive ingredients which, when incorporated in a hydrocar bon lubricating oil, not only improves-the oil in accordance with their individual func impartsa degree of improvement which greater than the additive combination of their individual improving properties. The cooperation or the two components of the combination produces additive composition possessing some improving so nents of the'combination have been generically disclosed and claimed by RushF. McCleary in application, Serial No. 411,696, filed September 20, 1941, and application, Serial No.'418,161, filed November 7, 1941. These compounds may be more specifically described by the; following'type formula:- i

where R indicates an oil-solubilizing radical which may be an alkyl, aralkyl, cycloalkyl or naphthenyl radical; A represents a carbocyclic radical which may be either an aromatic or alicyclic radical, preferably containing one cyclic nucleus; X may be either oxygen or sulfur; Y represents a metal salt of an alkylol or a thioalkylol radical; and n and m are integers of at least one. The substituent R is preferably an aliphatic-type radical containing a suflicient. number of carbon atoms to insure oil-solubility of the compounds and may be further substitutedfby radicals imparting additional improving qualities thereto, inthe form of radicals containing such elements as phosphorus, sulfur, ni-

trogen, etc.

one but The metal salts of the alkylol radicals represented .by Y comprise the salts of metals selected from groups I, II, IV and VIII of the periodic table of elements and include such metals as copb rfcalcium, strontium, barium, magnesium, ainc,

tin, lead, iron, cobalt and nickel with preference following:

given to the alkaline earth metals. The alkylol and thio-alkylol'radicals within the designation Y are preferably those containing from one to ten carbon atoms which may be either straight or branch chain radicals as illustrated by the Among the specific compounds included in the above category which have been found tobe exceptionally effective for the purposes of the present invention are calcium diamyl phenoxy ethylate, calcium diamyl cyclohexoxy; ethylate,

calcium cardanoxy ethylate (derived from car- -drocarbon lubricating oil invarying ratios, de-" pending upon the type of service for which the danol CaoHazO), calcium capryl phenoxy ethylats,'.

tin diamyl phenoxy ethylate, barium diamyl phenoxy ethylate and calcium keryl phenoxy ethylate (derived from phenol alkylated with kerosene).

The other additive component, namely an oil miscible N-aliphatic dithiocarbamate, has previously been proposed as a lubricating oil additive in Patents Nos. 2,160,880 and 2,265,851. The

which are illustrated by Formula 2 when z represents a metal. The metal salts are less 011- soluble than the-esters and,'in order to insure the oil-miscibility of the metal salts it ispreferable to limit the aliphatic radicals R1 and R:

to such radicals whose sum (R1+R:) contains at least six carbon atoms. This limitation, however, does not apply when'Z is an ester radical and probably because suflicient oil-solubility is imparted to thecompound by the ester radical itself. Among the specific compounds within this classification found to be particularly effective as a component of this additive combination are tin diamyl dithiocarbamate, zinc di (2-ethylhexyl) dithiocarbamate, zinc dibutyl dithiocarbamate, zinc octyl-butyl dithiocarbamate, zinc viso-amyl-n-amyl dithiocarbamate and benzyl diethyl dithiocarbamate.

The components of the aforementioned additive combination may be incorporated in a hylubricant is intended and the degree of improve- .ment desired. For all practical purposes the 1 amount, of either component added to the hydrocarbon oil will lie within the range of 0.01-

5.0% by weight of the finished, lubricant. The

specific range of proportions,- together with the I preferred range which has been found to give the maximum improvement in a few of the more important types of services: is indicated in the following table. For simplicity. the oil-miscible metal salt-of a carbocyclic alkylol ether component will be represented by A, and the oil-miscible N-aliphatic dithiocarbamate componentqwill be represented by B:

i l= Per cent by Per cent by weight weight Heavy duty Diesel and motor oils 0. 2&-3. 0 0.25-5. 0

' V a (0.7 1.0) (0. a0. 15

Motor oils .l 0.1 l. 0 0. 25-2. 0

Aircraft engine oils 0.1 l. 0 0. 26-1. 5

' The lmproving qualities of. this combination of additives when incorporated in a hydrocarbon oil, and particularly in a mineral lubricating oil.

are apparently due to some interaction between the two component molecules which alters the chemical activity of the individual component when incorporated in a hydrocarbon lubricating oil. This has been substantiated by the behavior of these additive components in numerous tests designed to predict the degree of improvement imparted by these additives to hydrocarbon lubricating oils under actual operating conditions.

One of these tests which is called a bearing stain test, is used to determine the amount and type of film which a'compounded oil will leave 1 i on the bearing surface. This type of test when in which R1 and Ra-are aliphatic radicals and Z represents either an ester radical such as an albl, aryl, aralkyl, cycloalkyl or a, naphthenyl radical or a metal selected from groups I, II.- III,

IV and VIIIof the periodic table of elements.

Specific samples of the metals contemplated within this classification are copper, magneslum, zinc, cadmium, aluminum, tin, lead, chromium, iron, cobalt and nickel, with preference given to tin, zinc and the-iron sub-group metals. The dithiocarbamates which have been found to be especially desirable are the met l used'in conjunction with acorrosion test tends to indicate the behavior of the additive with respect to bearing protection in an engine. Ac-' cording tothe procedure of this test,- a

1%; x section was" cut from a' copperlead bearing, cleaned, polished and placed in a four-ounce bottle. A suilicient amount of the test oil necessary to cover the bearing was added and the'stopped bottle inserted in an oil bath and maintained at a temperature of 30051". for six hours. At the completion of the six-hour heating period thetest specimen was removed,

$8.1 '175 washed in petroleum naphtha and examined. The

2,366,689 appearance of the bearing specimen was then fined, dewaxed Mid-Continent lubricating oil of' COPPER-LEAD BEARING Sum TEST-4300" F.

A B Bearing condition I Per cent Per cent 0. 25 Golden stain on part of bearing. 0. 25 Very dark peacock stain to grey coating.

0.25 0.25 Clecn-bright copper appearance. 4 0. 75 o. 5 Do. v i l Theforegoing test results indicate that although each of the individual components stains the bearing specimen, the combinations thereof provide a clean bearing. This test cannot be used to predict thedegree of bearing protection afforded by the additives but gives an indication of whether or not the bearing protection, if any. is a function of the film formation.

In order to show the bearing protection or anti-corrosive properties of the additives, the experimental oils'are subjected to an empirical test designed tosimulate actual corrosive conditions in an internal combustionengine. This test was conducted in an apparatus consisting of a copper-lead bearing specimen encased in-a special non-wearing bushing, rotatably mounted on a stainless steel shaft, and immersed in a glass pot of the oil to -be tested. This oil was heated to a controlled temperature of 350 F. and continuously circulated between the bearing specimen and the shaft for a period of hours. Throughout the test the oil was continuously maintained in a turbulent flow by copper baffles which acted resents zinc dibutyl dithiocarbamate, and B2 represents zinc dioctyl dithiocarbamate:

BEARING CORROSION-COPPER-LEAD 1o dorms) Loss of weighE-Mqs. Reference oil 242-222 Reference oi1+0.5% A1 283 Reference oil+0.25% Bl 66 Reference oil-+05% B2 142-107 Reference oil+0.5% A1+0.25% B1 1-2 Reference oil+0.5% A1+0.5% B2 1-1 As indicated by the results of the foregoing corrosion test, the A component when incorporated individually in the oil is considerably more corrosive than the reference oil and the B components, taken individually, are still moderately corrosive. However, in spite of the corrosive tendencies of the individual components, the combinations thereof render the oil substantially non-corrosive.

A test of this additive combination was also made in a single cylinder high speed CFR engine which is used to determine the detergency of aircraft engine oils underconditions which correlate actual service operation. This engine was operated-for hours at 1800 R. P. M. with a compression ratio of 6.5: 1, a manifold pressure of 40 inches mercury absolute, a jacket temperature of 285 F'., and with an oil pressure of 100 pounds per square inch. The lubricating system was initially charged with seven pounds of oil, which was drained to a five pound level every ten hours, and two pounds ofnew oil added. At the end of the fifty hour test period the piston was removed and examined. The reference oil in this .test was. a commercial uninhibited aircraft engine oil having a Saybolt viscosity of 120 at 210 F. The results obtained from'the reference oilwere then used in comparison with the reference oil containing varying proportions of the individual additive components, together with combinations thereof. The results are indicated in the following table where A1 represents calcium diamyl phenoxy ethylate and B1 represents zinc dibutyl dithiocarbamate:

HIGH SPEEDYCFR Danae-Error Tmsr ReicrenceoiL. Rcferenccoil+0.25% A. 0f pis Reference oil+l.5% B

rin grooves.

'Rciercnceoil+1.0% B1. 80% of piston skirt area ring grooves. Black Reference nil+0.25% A i-0.5% B1.

Reference ou t-0.25% A1+0.25% B,

' men was weighed before the test and after the lack lacquer in Nos. 2 3 and 4 grooves. All tin s la (is 414% of piston skirt area cov r g n covered ed with heavy black Black lacquer in Nos. 3 and 4 rln Valve: stem covered with black g grooves Alllands covered with black lacquer.

with black lacquer.

tarry lacquer Granular deposits in N as. l and 2 lacquer.

covered with heavy black tarry lacquer. Granular deposits in Nos. 1 and 2 lacquer in Nos. 3 and 69 K 8]? stgm (rigged with blacg lgcquer. 0 pis on s i area covere ve thin olden l alve stem clean. Light bl y ry g acquer 4 ring grooves. All lands covered with black lacquer.

As the results of this test indicate, the uncompounded aircraft engine oils possess the tendency of coating almost the entire piston area with a heavy black lacquer which builds up to a considerable thickness and is not easily removed in service. These oils also deposit granular carbonaceous deposits in the' ring grooves, particularly in the first two or three ring grooves, which seriously reduce the operating periods of the engine and usually result in ring sticking. By the addition of a small portion of component A the amount of lacquer formation is decreased, but the type of laccuer still remains the tions should be imposed appended claims.

same as that produced by the reference oil. The deposits in the ring grooves are similar to those of the reference oil in that granular carbonaceous deposits are still found in the top ringgrooves.

When adding small amounts of component B" to the reference oil the type of lacquer formed I on the piston is changed to a heavy black lacquer,

containing each of the components individually.

This lacquer is a very thin golden film, actually covering a very small portion of the piston area. In some of the test runs on this combination there, was no evidence of any granular carbonaceous deposits in the top ring grooves and only a I thin black to brown lacquer formation in the remaining grooves. I

Obviously many modifications and variations of the invention, as hereinbefore set forth, may be made without departin from the spirit and cope thereof and, therefore, only such limitaas are indicated in the We claim: 1. A lubricating composition comprising a hydrocarbon lubricating oil and the combination of OBI-5.0% by weight of an oil-miscible metal salt of a carbocyclic alkylol ether, said alkylol-radical containing from one to ten carbon atoms, said carbocyclic radical being selected from the group consisting of aromatic and alicyclic radical 0.01-

5.0% by Weight of an oil-miscible N-aliphatic dithlocarbamate. I 2. A lubricating composition comprising a hydrocarbon lubricating oil and the combination of 0.01-5.'0% by weight of an oil-miscible alkaline earth metal salt of a' carbocyclic alkylol ether and (Ml-5.0% by weight of an oil-miscible metal salt of an aliphatic dithiocarbamic acid. 3. A lubricating composition comprising a hydrocarbon lubricating oil and the combination of OBI-5.0% by weight of an oil miscible alkaline in which R1 and R: are aliphatic radicals, the sum of which contains at least six carbon atoms, and Z is an ester radical selected from the group consisting of aryl, aralkyl,cycloalkyl, and naphthenyl radicals.

, 5. A lubricating composition comprising a hydrocarbon lubricating oil and the combination of 0.01-5.0% by weight of an oil-miscible metal salt of a carbocyclic alkylol ether or the following general formula:

. Rn,A-'--(X-Y)m in which R is an aliphatic radical; A is a carbocyclic radical selected from the group consisting of aromatic and alicyclic radicals; X is an element from the group consisting of oxygen and sulfur; Y is a radical from the group consisting of metal salts of alkylol and thio alkylol radicals;

n and m are integers of at least 1; and 0.01- 5.0% by weight of an oil-miscible N-aliphatic dithiocarbamate of the following general formula:

N-c-s -z Rs in which R1 and R: are aliphatic radicals, the sum of which contains at least six carbon atoms and Z is a metal.

6. A lubricating composition comprising a hydrocarbon lubricating oil and the combination of 0.0l-5.0% by weight of an oil-miscible metal salt of a carbocyclic alkylol ether of the following general formula:

in which R. is an aliphatic radical; A is a carbocyclic radical; X is an element from the group consisting of oxygen and sulfur; Y is a radical from the group consisting of alkaline earth metal salts of alkylol and thio-alkylol radicals; n and m are integers of at least 1; and 0.1-5.0% by weight I of an oil-miscible N-aliphatic dithiocarbamate of earth metal salt of a carbocyclic alkylol ether and 0.0l-5.0% by weight of an oil-miscible metal salt of a dialkyl dith'iocarbamlc acid.

4. A lubricating composition'comprising a hy-- drocarbon lubricating oil and the combination of 0.015.0% by weight of an oil-miscible metal salt of a carbocyclic alkylol ether general formula:

of the following 1 in whichl't is an oil-solubilizing radical: A is a carbocyclic radical; X is an element from the group consisting of oxygen and sulfur; Y is a radical from the group consisting of metal salts of alkylol andthio-alkylol radicals; n and m are integers of at least 1; and om-5.0% by weight of an oil-miscible N-aliphatic dithiocarbamate of the following general formula: K i a I general formula:

the following general formula:

N( J-S-Z Ri in which R1 and R2 are aliphatic radicals, the

sum of which contains at least six carbon atoms,

and Z is a metal.

7. A lubricating composition comprising a hydrocarbon lubricating oil and the combination of 0.01-5.0% by weight of an oil-miscible metal salt of a carbocyclic alkylol ether of the followin in which R is an aliphatic radical: A, is a carbo cyclic radical; X is an element from the group consisting of oxygen and sulfurfY is a radical from the group consisting of alkalineearth metal I salts of alkylol and thio-alkylol radicals, said al- I ble N-aliphatic dithiocarbamate of, the

kylol or thio-alkylol radicals containing from one to ten carbon atoms; n and m are integers of at least 1; and 0.01- 5.0% by weight of an oil-miscifollowing general formula: I

Ra in which R1 and R2 are aliphatic radicals, the sum of which contains at least six carbon'atoms,

' andZ isametal.

a. A lubricating composition comprising a hydrocarbon lubricating oil and the combination of 0.01-5.0% by weight of an oil-miscible alkaline earth metal salt of a carbocyclic alkylol ether of the following general formula:

in which R is an oil-solubilizing radical; Ale a carbocyclic radical; X is an element from the group consisting of oxygen and sulfur; Y is a. radical from the group consisting of alkaline earth metal salts of alkylol and thig-alkylol radicals; n and m are integers of at least '1; and Obi-5.0% by weight of an oil-miscible N-aliphatic dithiocarbamate of the following general formula:

in which R1 and R2 are aliphatic radicals, and Z is a metal. 7

9. A lubricating composition comprising a hydrocarbon lubricating-oil and the combination of 0,0140% by weight of an oil-miscible metal salt of a carbocyclic alkylol ether of the following general formula:

I in which R is an oil-solubilizing radical: A is a carbocyclic radical; X is an element from the group consisting of oxygen and sulfur; Y is a radical from the groupconsisting of metal salts of alkylol and thio-alkylol radicals; n and mare integers of at least 1; and Dbl-5.0% by weight of an oil-miscible N-aliphatic dithiocarbamate of th following general formula:

R11-A--(X-,-Y)m in which R is an aliphatic radical; A is a carboperiodic in which R is an aliphatic radical; A is a carbo cyclic radical; X is oxygen; Y isa metal salt of an alkylol radical, said alkylol radical containing from 1 to 10 carbonatoms; n and m are integers of at least 1; and 0.01-5.0% by weight of an oil-miscible N-aliphatic dithiocarbamate' of the following general formula: I

in which R1 and R2 are aliphatic radicals, the sum' of which contains at least-r6 carbon atoms, andZisametal. I

11. A lubricating composition comprising a hydrocarbon lubricating oil and the combination of 0.01- 5.0% by weight of an oil-miscible metal salt .of a carbocyclic alkylol ether of the general formula:

Rn-A- (X-Y) m in which R is an aliphatic radical; A is a carbocyclic radical x is oxygen: Y is a metal salt of following an 111117101 radical, said alkylol radical containing from 1 to 10 carbon atoms; 1 and m are integers of at least 1; and 0.1'-5.0% by weight of an oil miscible N-aliphatic dithiocarbamate of the following general formula:

in which R1 and R: are aliphatic radicals, the sum of which contains at least 6 carbon atoms, and Z is a metal from the class consistingof tin, zinc and the iron sub-group metals of the table of elements. I

12. A lubricating composition comprising a hydrocarbon lubricating oil and the combination of 0.01-5.0% by weight of an oil-miscible metal salt of a carbocyclic alkylol ether of the following general formula:

EPA-4 xn m cyclic radical selected from the group consisting of aromatic and alicyclic radicals; X is an element from the group consisting of oxygen and sulfur; Y is a radical from the group consisting of metalsalts of alkylol and thio-alkylol radicals; n and m are integers'of at least 1; and Mil-5.0% by weight of an oil-miscible N-aliphatic dithiocarbamate of the following general formula:

in which R1 and Rs are aliphatic radicals, the carbon atoms,

sum of which'contains at least six and Z is an ester'radical.

13. Alubricating composition comprising a hydrocarbon lubricating oil and the combination of 0.0l-5.0% by weight of an oil-miscible metal salt I of a carbocyclic alkylol ether of the following general formula:

Raw-A-(X-Y).

in which R is an aliphatic radical; A is a carbocyclic radical; X is an element from the group consisting of oxygen and sulfur; Y is a radical from the group consisting of alkaline earth metal salts of alkyiol and thio-alkylol radicals; n and m are integers of at least 1; and 0.01-5.0% by weight of an oil-miscible Nealiphatic dithiocarbamate of the following general formula:

Jl s z in which R1 and Re are aliphatic radicals. the sum of which contains at least six carbon atoms, and

Zisanesterradical. I,

14. A lubricating composition comprising a hy- 1 drocarbon lubricating oil and the combination of 0.01-5.0% by weight of an oil-miscible metal salt of a carbocyclic alkylol ether of the following general formula:

I RaA -(XY)m in which R is an aliphatic radical; A is a carbocyclic radical; X is an element from the group consisting of oxygen and sulfur: Y is a. radical from the group consisting of alkaline earth metal A I salts of alkylol and thio-alkylol radicals, saidalkyloi or thio-alkylol. radicals containing'from one to tencarbon atoms; 11 and m are integers of at least 1; and (mi-5.0% by weight of an oilperiodic miscible N aliphatic dithiocarbamate of the following general formula:

in hich Rrand R2 are aliphatic radicals, the sum I of which contains at least six carbon atoms, and

Z is an ester radical.

15. A lubricating composition comprising a hydrocarbon lubricating oil and the combination of 0.01-5.0% .by weight of an oil-miscible metal salt of a carbocyclic alkylol ether or the following A general formula: a

' lowing general formula:

0.01-5.0% by weight of an oil-miscible allraline I earth metal salt of a carbocyclic alkylol ether, and

in which R1 and Rs are aliphatic radicals, the sum I v of which contains at least six carbon atoms, and Z' is an ester radical 16. A lubricating composition comprising a hydrocarbon lubricating oil and the combination of 0.01-5.0% by weight of an oil-miscible alkaline earth metal salt of an aliphatic phenoxy ethanol.

phatic dithiocarbamate.

17. A lubricating composition comprising a hydrocarbon lubricating oil and the cpmbination or o.o1-5.o% by weight oi ,a zinc salt or a dialkyl dithiocarbamic acid.

18. A lubricating composition comprising a mineral lubricating oil and the combination of '0.015.0% by weight of an oil-miscible alkaline earth metal salt of a dialkyl phenoxy ethanol, and

0.0l-5.0% by weight of an oil-miscible zinc salt of a dialkyl dithiocarbamic acid. 19. A lubricating composition comprising a hy.

drocarbon oil and the combination or 0.01-5.0%

by weight of anon-miscible metal salt of a carbocyclic alkylol ether, and (ml-5.0% by weight of an oil-miscible N-aliphatic dithiocarbamate.

20. A lubricating composition comprising a hydrocarbon lubricating oil and the combination of o.01-5.o% by weight 0! an oil-miscible metal salt of a carbocyclic alkylol ether of the following general formula:

in which R is an oil-solubilizing radical; A is a carbocyclic radical; X is an element from the group consisting of oxygen and sulfur; Y is a I radical from the group consisting of metal salts of alkylol and thio-alkylol radicals, n and m are integers of at least 1; and 0.01-5.0% by weight 01' an oil-miscible N-aliphatic dithiocarbamate of t0 the following general formula:

and 0.01-5.0% by weight of an oil-miscible N-aliin which R1 and Re are aliphatic radicals, and Z is a metal.

' RUSH F. MCCLEARY.

JOSEPH E. FIELDS.- 

